Provided is a fluid-cooled contact tip assembly that can be used in methods and systems for manufacturing objects by solid freeform fabrication, especially titanium and titanium alloy objects, where the deposition rate is increased by increasing the flow rate of electric charge through the metal wire.

Plasma torch with an integrated electrode incorporating many heat pipes each heat pipe comprises an evaporating section and a condensing section set at a front end and a rear end of the electrode, respectively. The heat pipes with extremely high thermal conductivity can be used to replace the traditional water-cooled torch's electrode. The effect of reducing the elevated temperature at the torch's arc root zone through cooling by heat pipes is beneficial for prolonging the lifetime of plasma torch. Each heat pipe is filled with a small amount of working fluid. Even if one heat pipe is etched out, the cooling liquid thus ejected is limited without causing gas explosion and rock curing; the rest of heat pipes are not damage and can still function; although the heat dissipation efficiency might be reduced a little, the plasma torch still works. Thus, flexibility of the whole heat dissipation is enhanced.

Plasma torch with an integrated electrode incorporating many heat pipes each heat pipe comprises an evaporating section and a condensing section set at a front end and a rear end of the electrode, respectively. The heat pipes with extremely high thermal conductivity can be used to replace the traditional water-cooled torch's electrode. The effect of reducing the elevated temperature at the torch's arc root zone through cooling by heat pipes is beneficial for prolonging the lifetime of plasma torch. Each heat pipe is filled with a small amount of working fluid. Even if one heat pipe is etched out, the cooling liquid thus ejected is limited without causing gas explosion and rock curing; the rest of heat pipes are not damage and can still function; although the heat dissipation efficiency might be reduced a little, the plasma torch still works. Thus, flexibility of the whole heat dissipation is enhanced.

The invention relates to an electrode (30) for an especially gas-cooled plasma torch (10), in particular plasma cutting torch, the electrode comprising: an elongated electrode body (30b) with an open end (34) and a closed end (33), said ends defining a longitudinal axis L, and an emission insert (31) in the closed end (33), a cavity (32; 32a, 32b) extending in the electrode body (30b) from the open end (34) of the electrode body towards the closed end (33), said cavity fluidically communicating with the outer face (37) of the electrode body which is radial with regard to the longitudinal axis, via at least one opening (32c, 32d) in its wall (30a) or in the front solid portion of the closed end (33). The invention further relates to a system consisting of said electrode and cooling tube, to a gas conducting unit, a plasma torch comprising same, a method for conducting gas in a plasma torch and a method for operating the plasma torch.

The invention relates to an electrode (30) for an especially gas-cooled plasma torch (10), in particular plasma cutting torch, the electrode comprising: an elongated electrode body (30b) with an open end (34) and a closed end (33), said ends defining a longitudinal axis L, and an emission insert (31) in the closed end (33), a cavity (32; 32a, 32b) extending in the electrode body (30b) from the open end (34) of the electrode body towards the closed end (33), said cavity fluidically communicating with the outer face (37) of the electrode body which is radial with regard to the longitudinal axis, via at least one opening (32c, 32d) in its wall (30a) or in the front solid portion of the closed end (33). The invention further relates to a system consisting of said electrode and cooling tube, to a gas conducting unit, a plasma torch comprising same, a method for conducting gas in a plasma torch and a method for operating the plasma torch.

A torch head for a liquid-cooled plasma arc torch is provided. The torch head includes a torch body and a torch insulator, coupled to the torch body, having a substantially non-conductive insulator body. The torch insulator includes (i) a first liquid coolant channel, disposed within the insulator body, configured to conduct a fluid flow from the torch head into a consumable cartridge along a first preexisting flow path, (ii) a first liquid return channel, disposed within the insulator body, configured to return at least a portion of the fluid flow from the cartridge to the torch head along the first preexisting flow path, and (iii) a gas channel, disposed within the insulator body, configured to conduct a first gas flow from the torch head to the cartridge along a second preexisting flow path. The first and second preexisting flow paths are fluidly isolated from each other.

A torch head for a liquid-cooled plasma arc torch is provided. The torch head includes a torch body and a torch insulator, coupled to the torch body, having a substantially non-conductive insulator body. The torch insulator includes (i) a first liquid coolant channel, disposed within the insulator body, configured to conduct a fluid flow from the torch head into a consumable cartridge along a first preexisting flow path, (ii) a first liquid return channel, disposed within the insulator body, configured to return at least a portion of the fluid flow from the cartridge to the torch head along the first preexisting flow path, and (iii) a gas channel, disposed within the insulator body, configured to conduct a first gas flow from the torch head to the cartridge along a second preexisting flow path. The first and second preexisting flow paths are fluidly isolated from each other.

A nozzle for a liquid-cooled plasma arc torch is provided. The nozzle includes a thermally conductive body having a distal end, a proximal end, and a longitudinal axis extending therethrough. The nozzle also includes a plasma arc exit orifice at the distal end of the thermally conductive body. The nozzle additionally includes a cooling waist located circumferentially about an exterior surface of the thermally conductive body. The cooling waist includes a liquid inlet slope, a liquid outlet slope and a heat exchange region between the liquid inlet slope and the liquid outlet slope. The heat exchange region extends substantially parallel to the longitudinal axis, and the liquid inlet slope and the liquid outlet slope are oriented generally perpendicular to the longitudinal axis.

A nozzle for a liquid-cooled plasma arc torch is provided. The nozzle includes a thermally conductive body having a distal end, a proximal end, and a longitudinal axis extending therethrough. The nozzle also includes a plasma arc exit orifice at the distal end of the thermally conductive body. The nozzle additionally includes a cooling waist located circumferentially about an exterior surface of the thermally conductive body. The cooling waist includes a liquid inlet slope, a liquid outlet slope and a heat exchange region between the liquid inlet slope and the liquid outlet slope. The heat exchange region extends substantially parallel to the longitudinal axis, and the liquid inlet slope and the liquid outlet slope are oriented generally perpendicular to the longitudinal axis.

The design and implementation of a thermally optimized neutrode stack for cascaded plasma guns is provided that reduces the thermal loss to the water while minimizing peak stack temperatures. Optimizing the cooling will permit longer stacks to be used without the penalty of high thermal losses.